iron had got very red, and I could see that he was blaspheming
violently under his breath. Mary's eyes were quiet and solemn. She kept
on patting Sir Walter's hand. The sense of some great impending
disaster hung heavily on me, and to break the spell I asked for details.

'Tell me just the extent of the damage,' I asked. 'Our neat plan for
deceiving the Boche has failed. That is bad. A dangerous spy has got
beyond our power. That's worse. Tell me, is there still a worst? What's
the limit of mischief he can do?'

Sir Walter had risen and joined Blenkiron on the hearthrug. His brows
were furrowed and his mouth hard as if he were suffering pain.

'There is no limit,' he said. 'None that I can see, except the
long-suffering of God. You know the man as Ivery, and you knew him as
that other whom you believed to have been shot one summer morning and
decently buried. You feared the second--at least if you didn't, I
did--most mortally. You realized that we feared Ivery, and you knew
enough about him to see his fiendish cleverness. Well, you have the two
men combined in one man. Ivery was the best brain Macgillivray and I
ever encountered, the most cunning and patient and long-sighted.
Combine him with the other, the chameleon who can blend himself with
his environment, and has as many personalities as there are types and
traits on the earth. What kind of enemy is that to have to fight?'

'I admit it's a steep proposition. But after all how much ill can he
do? There are pretty strict limits to the activity of even the
cleverest spy.'

'I agree. But this man is not a spy who buys a few wretched
subordinates and steals a dozen private letters. He's a genius who has
been living as part of our English life. There's nothing he hasn't
seen. He's been on terms of intimacy with all kinds of politicians. We
know that. He did it as Ivery. They rather liked him, for he was clever
and flattered them, and they told him things. But God knows what he saw
and heard in his other personalities. For all I know he may have
breakfasted at Downing Street with letters of introduction from
President Wilson, or visited the Grand Fleet as a distinguished
neutral. Then think of the women; how they talk. We're the leakiest
society on earth, and we safeguard ourselves by keeping dangerous
people out of it. We trust to our outer barrage. But anyone who has
really slipped inside has a million chances. And this, remember, is one
man in ten millions, a man